Synergistic strategy of Z-scheme heterojunction and defect engineering to construct ZnS/CoSx nanospheres for excellent photocatalytic H2 evolution performance

Abstract

The design of Z-scheme heterojunction to realize the efficient separation of charge carriers still remain challenging. Herein, the defect-assisted Z-scheme heterojunction strategy has been proposed. The binary ZnS/CoSx nanospheres were successfully prepared via a well-designed hydrothermal approach. The resultant ZnS/CoSx nanospheres with CoSx content of 5 wt% exhibit the optimal hydrogen production rate of 2546.6 μmol g−1h−1, which is 2.6 times higher than that of pure ZnS and superior to the most reported ZnS-based composites. The enhancement of S-vacancy concentration can greatly strengthen photocatalytic hydrogen evolution property, which can be originated from the boosted direct Z-scheme charge-transfer process in ZnS/CoSx heterostructures. The synergistic effect of direct Z-scheme heterostructures and defects engineering notably enhances the photocatalytic activity of ZnS/CoSx nanospheres, which could provide a deep insight for the design and synthesis of new types of photocatalysts.